- Method for preparing N-methyl azepine-4-one hydrochloride
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The invention discloses a method for preparing N-methyl azepine-4-one hydrochloride. According to the method, 4-oxime cyclohexanone is taken as a raw material, aza-cycloheptane-2,5-diketone is obtained under a Beckmann rearrangement condition, aza-cycloheptane-2,5-diketone and ethylene glycol are subjected to condensation to generate ketal, amide is reduced through red aluminum, methylation is performed, ethylene glycol is removed under a hydrochloric acid condition, and finally N-methyl azepine-4-one hydrochloride is obtained. The invention provides a safe, reliable and efficient synthetic route, the raw materials are low in price, the reaction conditions are mild, explosive diazomethane does not need to be used, methyl acrylate which is easy to polymerize and high in carcinogenesis is also not needed, and the method is more suitable for large-scale industrial production.
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- Preparation method of azelastine key intermediate N-methylhexahydroazepine-4-ketone hydrochloride
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The invention belongs to the technical field of medicine synthesis, and particularly relates to a preparation method of an azelastine key intermediate N-methylhexahydroepine-4-ketone hydrochloride. Aiming at the problems that in the prior art, a synthetic route of N-methylhexahydroepine-4-ketone hydrochloride uses more organic raw materials, so that the cost is increased, the environmental protection is not facilitated, and the impurity content in a product is increased, the technical scheme of the invention is as follows: N-methyl-2-pyrrolidone is used as an initial raw material and is subjected to alkaline hydrolysis, and substitution addition and esterification are sequentially carried out, and then cyclization is carried out to synthesize the azelastine key intermediate. The method issuitable for industrial production of the azelastine key intermediate N-methylhexahydroepine-4-ketone hydrochloride.
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- Method for the preparation of hexahydroazepinones and hexahydroazepinoles
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This disclosure describes two technical procedures for the high-yield synthesis of heterocyclic seven-membered ring-systems by Dieckmann-condensation avoiding usual dilution techniques and long reaction times. Thus, it significantly increases the overall yields of the pharmaceutically active ingredients azelastine and flezelastine, whose synthesis, starting from these seven-membered heterocyclic rings, is reported elsewhere. Yields range from 80-89%, avoiding waste and increasing economics of the synthesis.
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